Chapter 5, Problem 5.9E

True or false Heat is transferred to a system by either a cheap commercially available air-sourced heat pump with coefficient of performance of just 1.5, or an expensive 100% efficient electrical resistance heater. The loss of Carnot Work Potential (Exergy destruction, or T0Sloss term) is minimum when heat is added by the cheap commercial heat pump.   Heat is transferred to a system by either a cheap commercially available air-sourced heat pump with coefficient of performance of just 1.5, or an expensive 100% efficient isothermal heat source. The loss of Carnot Work Potential (Exergy destruction, or T0Sloss term) is minimum when heat is added by the isothermal heat source.

1. Explain the environmental aspects of Thermal power generation with a neat diagram. 2. Describe the renewable energy sources in OMAN with a neat diagram.

Is renewable energy really the solution to the emerging power crisis?

Answer it broadly.

Define as energy systems that have the capability to produce two useful outputs simultaneously. combined cycle systems B. cogeneration systems (C) complex generation systems coordinated generation systems

A heat source supplies 2325 kJ/kg to a working substance in a closed thermodynamic power cycle. The sink receives 1510 kJ/kg of working substance. The system pump requires 14kJ/kg of substance pumped. What is the thermal efficiency of the cycle?

1. Describe two fact that identify the inadequacy of the First law of thermodynamics compare to the second law of thermodynamics and name the property that supports the facts. 2.Describe the thermal energy reservoir and identify the source and sink for a case of laptop used in an office room space. 3.In the four processes that make up the Carnot cycle, briefly illustrate in your own words on how the reversible isothermal and adiabatic process are achieved during expansion and compression.

1. A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of 0.4 bar and 35 bar. Steam enters the boiler as a saturated liquid and leaves it as a dry saturated vapour. (i) List the name of the four processes in a generic Carnot cycle and state what type of energy transfer (work/heat) can be neglected in each process. (ii) Sketch a T-s diagram for the above cycle indicating the location of the four components required. (iii) Determine the dryness fraction of the steam that is fed to the condenser.

(A) the net heat energy absorbed during a cyclic process (the difference between heat flowing into the system and heat leaving the system) is the work. If we regard the atmosphere as a heat engine, what is the work being done by the atmosphere? That is, what phenomenon or phenomena are a realization of the work being done by the atmosphere? (B) Of all possible heat engines, the Carnot cycle has the maximum efficiency between any two operating temperatures (think of these temperatures as the maximum and minimum temperatures encountered during the cycle). Estimate the Carnot efficiency of Earth's atmosphere. [Hint: Think about the temperature variation with latitude.] (C) Do you think the efficiency of the real atmosphere would be "close" or "far" from the Carnot efficiency? Please explain your answer.